scholarly journals Complexity Analysis of Electroencephalogram Dynamics in Patients with Parkinson’s Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Guotao Liu ◽  
Yanping Zhang ◽  
Zhenghui Hu ◽  
Xiuquan Du ◽  
Wanqing Wu ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Complexity Analysis ◽  
Normal Subjects ◽  
New Combination ◽  
Discrete Wavelet ◽  
Eeg Signal ◽  
Combination Scheme ◽  
Electroencephalogram Eeg ◽  
Split Frequency

In this study, a new combination scheme has been proposed for detecting Parkinson’s disease (PD) from electroencephalogram (EEG) signal recorded from normal subjects and PD patients. The scheme is based on discrete wavelet transform (DWT), sample entropy (SampEn), and the three-way decision model in analysis of EEG signal. The EEG signal is noisy and nonstationary, and, as a consequence, it becomes difficult to distinguish it visually. However, the scheme is a well-established methodology in analysis of EEG signal in three stages. In the first stage, the DWT was applied to acquire the split frequency information; here, we use three-level DWT to decompose EEG signal into approximation and detail coefficients; in this stage, we aim to remove the useless and noise information and acquire the effective information. In the second stage, as the SampEn has advantage in analyzing the EEG signal, we use the approximation coefficient to compute the SampEn values. Finally, we detect the PD patients using three-way decision based on optimal center constructive covering algorithm (O_CCA) with the accuracy about 92.86%. Without DWT as preprocessing step, the detection rate reduces to 88.10%. Overall, the combination scheme we proposed is suitable and efficient in analyzing the EEG signal with higher accuracy.

scholarly journals Discrete wavelet transform-based freezing of gait detection in Parkinson’s disease

2018 ◽  
pp. 1-17 ◽  
Author(s):  
Amira El-Attar ◽  
Amira S. Ashour ◽  
Nilanjan Dey ◽  
Hatem Abdelkader ◽  
Mostafa M. Abd El-Naby ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Freezing Of Gait ◽  
Discrete Wavelet

Increased Visual Dependence in Parkinson's Disease

2002 ◽  
Vol 95 (3_suppl) ◽  
pp. 1106-1114 ◽  
Author(s):  
Jean Philippe Azulay ◽  
Serge Mesure ◽  
Bernard Amblard ◽  
Jean Pouget
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Gait Analysis ◽  
Visual Information ◽  
Frontal Plane ◽  
Normal Subjects ◽  
Visual Control ◽  
Subjective Vertical ◽  
Visual Vertical ◽  
Visual Dependence

The present study tested the hypothesis that there is increased visual dependence perceptually in patients with Parkinson's disease. We also evaluated whether the visual control of posture and locomotion was related to perceptual visual field dependence. 21 patients with idiopathic Parkinson's disease and 22 age-matched normal subjects were compared on judgment of the visual vertical using the Rod-and-Frame test with visual perturbations in the frontal plane with a tilted frame. Patients had significantly larger errors than controls in the estimation of the subjective vertical. In the same experiment, we performed a posture and a gait analysis in both groups. Posturographic evaluation did not indicate significant differences in unsteadiness between patients and controls. Gait analysis indicated a typical pattern of reduced velocity, shortened stride length, and normal step width. A significant correlation of .89 was found only in the Parkinsonian group between their errors in estimating subjective visual vertical and the Romberg quotient evaluating visual contribution to postural control. No specific locomotor pattern was correlated with visual dependence. Considering our results and previous reports on the visual control of posture, we conclude that patients with Parkinson's disease showed a significantly increased dependence upon visual information both perceptually and motorically, with an increased perceptual visual dependence in the patients being predictive of an equivalent visual dependence or visual control of posture and equilibrium.

Hydroxylase cofactor activity in cerebrospinal fluid of normal subjects and patients with Parkinson's disease

Science ◽  
1979 ◽  
Vol 204 (4393) ◽  
pp. 624-626 ◽  
Author(s):  
W Lovenberg ◽  
R. Levine ◽  
D. Robinson ◽  
M Ebert ◽  
A. Williams ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cerebrospinal Fluid ◽  
Normal Subjects ◽  
Cofactor Activity

Dual Task Interference in Parkinson’s Disease

US Neurology ◽  
2009 ◽  
Vol 05 (01) ◽  
pp. 30 ◽  
Author(s):  
Tao Wu ◽  
Mark Hallett ◽  
◽  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dual Task ◽  
Human Life ◽  
Normal Subjects ◽  
Neural Correlates ◽  
Task Interference ◽  
Attentional Resources ◽  
Dual Task Performance ◽  
Dual Task Interference

Performing two tasks simultaneously (dual task performance) is a frequent activity in human life. Patients with Parkinson’s disease (PD) commonly have more difficulty in performing dual tasks than healthy people. To date, research on the mechanisms of dual task interference in PD remains sparse. A recent study by Wu and Hallett in 2008 investigated the central neural correlates of dual task interference in PD, and demonstrated that dual task interference in PD is due to multiple reasons. First, the limitation of capacity of attentional resources is exceeded; second, PD patients perform tasks less automatically compared with normal subjects; and third, the central executive may be defective. However, our knowledge of this phenomenon is still far from complete and needs further investigation.

Full length α-synuclein is present in cerebrospinal fluid from Parkinson's disease and normal subjects

2000 ◽  
Vol 287 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Roberta Borghi ◽  
Roberta Marchese ◽  
Alessandro Negro ◽  
Lucio Marinelli ◽  
Gianluigi Forloni ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cerebrospinal Fluid ◽  
Normal Subjects ◽  
Full Length

scholarly journals Blood Plasma of Patients with Parkinson’s Disease Increases Alpha-Synuclein Aggregation and Neurotoxicity

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Peng Wang ◽  
Xin Li ◽  
Xuran Li ◽  
Weiwei Yang ◽  
Shun Yu
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Alternative Pathway ◽  
Lewy Bodies ◽  
Normal Subjects ◽  
Alpha Synuclein ◽  
Phosphatase 2A ◽  
Alpha Synuclein Aggregation ◽  
The Brain ◽  
Neighboring Neuron

A pathological hallmark of Parkinson’s disease (PD) is formation of Lewy bodies in neurons of the brain. This has been attributed to the spread of α-synuclein (α-syn) aggregates, which involves release of α-syn from a neuron and its reuptake by a neighboring neuron. We found that treatment with plasma from PD patients induced more α-syn phosphorylation and oligomerization than plasma from normal subjects (NS). Compared with NS plasma, PD plasma added to primary neuron cultures caused more cell death in the presence of extracellular α-syn. This was supported by the observations that phosphorylated α-syn oligomers entered neurons, rapidly increased accumulated thioflavin S-positive inclusions, and induced a series of metabolic changes that included activation of polo-like kinase 2, inhibition of glucocerebrosidase and protein phosphatase 2A, and reduction of ceramide levels, all of which have been shown to promote α-syn phosphorylation and aggregation. We also analyzed neurotoxicity of α-syn oligomers relative to plasma from different patients. Neurotoxicity was not related to age or gender of the patients. However, neurotoxicity was positively correlated with H&Y staging score. The modification in the plasma may promote spreading of α-syn aggregates via an alternative pathway and accelerate progression of PD.

Disturbances of Rhythm Formation in Patients with Parkinson's Disease: Part II. A Forced Oscillation Model

1978 ◽  
Vol 46 (1) ◽  
pp. 79-87 ◽  
Author(s):  
H. Nagasaki ◽  
R. Nakamura ◽  
R. Taniguchi
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Forced Oscillation ◽  
Normal Subjects ◽  
Order System ◽  
Signal Frequency ◽  
Oscillation System ◽  
The Central Nervous System ◽  
Intrinsic Oscillation ◽  
Dirac Function

The origin of the characteristic disturbances of rhythm formation in patients with Parkinson's disease (the hastening phenomenon) was discussed, using a second-order system of the periodic response. The input signal was regarded as a pulse series of a Dirac function. The output process of the system had maximal errors of response at input frequencies of f = ω0/ n ( n = 1, 2, …), where ω0 was the intrinsic frequency of the system. Damping coefficient ε represented a function of an inhibiror against these maximal errors and the errors diverged to infinity when ε = 0. The solution of this forced oscillation system indicated that the intrinsic oscillation of the system had a possibility to be excited at these critical frequencies f = ω0/ n. Inferred from data on the tapping test, the frequency of an intrinsic oscillation was 5 Hz in the central nervous system, then the critical frequencies were predicted 5/ n = 5, 2.5, … Hz. On the tapping test the errors of response become maximum around 2.5 and 5 Hz (taps per second), and their peak heights increased from the minimum in well trained normal subjects to the maximum in patients. An inhibitory mechanism against the maximal error would function well, i.e., ε > 0, in normal subjects but so insufficiently (ε → 0) in patients that the excited intrinsic oscillation would control their response directly. Thus some patients could no longer maintain a synchronous tapping response at 2.5 Hz or 5 Hz and showed a hastened tapping of 5 ∼ 6 Hz independent of the signal frequency.

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